/Engine/Source/Runtime/Engine/Classes/Components/PrimitiveComponent.h
Creates a Dynamic Material Instance for the specified element index, optionally from the supplied material.
virtual [UMaterialInstanceDynamic](API\Runtime\Engine\Materials\UMaterialInstanceDynamic) * CreateDynamicMaterialInstance ( int32 ElementIndex, class [UMaterialInterface](API\Runtime\Engine\Materials\UMaterialInterface) * SourceMaterial, [FName](API\Runtime\Core\UObject\FName) OptionalName )